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        검색결과 157

        102.
        2016.11 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Prior literature expects a lower marginal cash value for weaker governance firms. We test this empirical hypothesis by using the sample of publicly traded Korean firms from 2005 to 2013. To measure the quality of governance structures, we employ the corporate governance scores provided by Korean Corporate Governance Services. The empirical model of Faulkender and Wang (2006) is adopted to estimate the marginal value of cash. Our empirical analysis shows a higher marginal value of cash for the good governance firms in the examination of the total governance score. This finding is consistent to the agency view of cash policy predicting a larger marginal value of cash for the firms with higher governance scores. However, this positive relationship is not robust for a subset of detailed governance scores; a lower marginal cash value is observed for the firms with better qualities of board structure, auditing, dividend policies. Moreover, our empirical analysis verifies a quite low level of marginal cash value for Korean firms, which supports the existence of severe agency conflicts in Korean corporations. Our results verify the significant role of agency conflicts between a manager and shareholders in the determination of marginal cash values in the Korean firms.
        103.
        2016.10 서비스 종료(열람 제한)
        Background : Campanula takesimana is a herb(Jabanpungnyeoncho) used traditionally in the korea private and we tried the development on a medicinal material. It was known that it has chlorogenic acid, as a immunoadjuvant activity. In this study we investigated the contents of the chlorogenic acid in Companula takesimana at different harversting time by the high performance liquid chromatographic(HPLC)-PDA. Campanula takesimana was collected on May maddle (Flower buds farmed), June middle (flowers opened) and July middle (seeds were mature). Methods and Results : HPLC analysis was carried out using X-bridge C18 column (5um, 250*4.6mm) and a mobile phase consisting of acetonitrile and water containing 0.1% formic acid at a flow rate of 1.0 ml/min. The optimum wavelength for the detection of the Chlorogenic acid was 330 nm using Photo Diode Array Detector. The contents of the chlorogenic acid in the Campanula takesimana extrat were 1.00% (May middle), 0.84% (June middle), 0.05% (July middle), respectively. As the different parts of Campanula takesimana, chlorogenic acid contents in May middle extrat were 2.73% (aerial part), 0.05% (root) and in June middle extrat were 1.61% (aerial part), 0.03% (root), 0.70% (flower) and in July middle were 0.13% (aerial part), 0.03% (root), 0.00% (seed), respectively. Conclusion : From the above results, the highes content of chlorogenic acid was observed in aerial part and May middle extract of Campanula takesimana.
        104.
        2016.10 서비스 종료(열람 제한)
        Background : Malonyl ginsenoside content of the Panax ginseng is known to account for 35% to 60% of total ginsenosides content. However, its distribution by ginseng part has not been studied. In this study, four kinds of malonyl ginsenosides were compared in Korean white ginseng part using the purified malonyl ginsenoside standards in our laboratory. Methods and Results : White ginseng was prepared by the air drying (50℃, 48h) or freeze drying (-70℃, 48h) methods form 4-year-old ginseng. Malonyl ginsenoside content in total ginsenosides were similar in air dried and freeze dried white ginseng, 58% and 62%, respectively. Therefore, malonyl ginsenoside contents in main, lateral, and fine root, and in the main root without skin and skin of main root prepared by freeze dried method were compared. Malonyl ginsenosides (m-Rb1, m-Rb2, m-Rc and m-Rd) and total ginsenosides (Rg1, Re, Rf, Rb1, Rc, Rb2, Rb3, Rd, m-Rb1, m-Rb2, m-Rc and m-Rd) were 6.75 and 14.15 mg/g in main root, 14.15 and 26.35 mg/g in lateral root, 46.95 and 84.15 mg/g in fine root. Malonyl ginsenoside contents in skin of main root was 20.08 mg/g, while its contents of the main root without skin was 2.58 mg/g. Conclusion : As a result, the parts each air drying the sample was confirmed that the ratio of the distribution of malonyl ginsenoside (main root : lateral : fine root = 18.7 : 11.1 : 16.2), and distribution ratio of main root, skin of main root, lateral, skin of lateral was found to be (12.2: 14.6 14.3: 3.7). Malonyl ginsenoside content was the highest in fine root, compared to the main or lateral root. Malonyl ginsenoside contents in skin of root was higher than those of the main root without skin. These results is expected to help establish an efficient extraction and standardization. Malonyl ginsenoside analysis of White ginseng using HPLC expects that the standardization process can be established.
        106.
        2015.07 서비스 종료(열람 제한)
        The high quality of gene set is necessary to study the functional research of genes. Although perilla is cultivated as an oil crop and as a vegetable crop in Asian countries such as Korea, Japan, northeast China and Nepal, the reference genome is absent. To assembly perilla gene set, we sequenced the various tissues of perilla (Perilla citriodora) RNA-seq with Illumina HiSeq platform, generating 548,549,314 short reads. When de novo transcriptome assembly was performed with five samples, 86,396 and 38,413 transcripts were assembled as total and representative transcripts, respectively. Using 1,917,424 proteins at Phytozome ver. 9.1, we annotated the perilla assembled transcripts, and 66,139(76.55%) and 24,030(62.55%) transcripts showed the similarity with known plant proteins (E-value < 1e-10) as total and representative transcripts, respectively. Among the diverse molecular functions, we were interested in the regulatory components, such as transcription factor and transcription regulator. Using this data, we identified 499 transcripts annotated the putative transcription factor differentially expressed transcripts. 165 putative transcription factors were significantly expressed in perilla flower and 121 putative transcription factors in both leaf and flower. This study provides the perilla reference gene set and the understanding of the molecular regulation of transcription factor dependent on the tissue.
        107.
        2015.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        본 연구에서 사용한 홍삼 전분은 홍삼 농축액 제조 공정에서 발생하는 부산물중 하나로 현재까지는 특별한 활용도가 없었다. 하지만 홍삼 농축액 제조 과정에서 발생되는 홍삼 유래의 물질로 홍삼의 유효 성분인 진세노사이드 및 각종 유리당, 탄수화물 등이 풍부한 안전한 소재로서의 가능성을 알아보고자 하였다. 홍삼전분을 이용한 새로운 홍삼막걸리의 차별화를 위하여 제품의 진세노사이드 함량, 유기산, 유리당, 효모수 등을 분석하였다. 효모 생균수의 변화 조사결과 4℃에서 저장하였을 때는 저장 20일까지 효모 균수에 큰 변화가 없었지만 25℃ 저장에서는 저장 20일에 초기 효모균수의 약 75%가 감소되었다. 유기산분석 결과 막걸리에서는 lactic acid가 4.16 mg/mL의 농도로 가장 많았으며, 그 다음으로는 citric acid 0.88 mg/mL, malic acid 0.39 mg/mL의 순서로 많았다. 저장 초기에는 malic acid의 함량이 4℃ 및 25℃에서 0.39 mg/mL 와 0.58 mg/mL 이었으나 저장일이 20일 경과하였을 때에는 0.46 mg/mL 그리고 0.17 mg/mL으로 측정되었고 대부분의 유기산은 저장기간에 관계없이 변화가 크게 나타나지 않았으나 butyric acid는 증가를 보였다. 20일 경에 lactic acid와 isobutyric acid는 감소하였으며 다른 종류의 유기산은 증가를 보였다. 유리당 분석결과 glucose가 4.4 mg/mL, sucrose 2.8 mg/mL 그리고 mannose 1.4 mg/mL 으로 막걸리의 주 구성당으로 분석되었으며 저장기간이 지속되면서 sucrose, glucose, mannose의 함량은 감소를 보여 알콜 발효의 주요 기질로 사용되었음을 보여주었다. 저장 4~8일 이후부터는 당이 급격히 감소하였으며 8일 이후부터는 큰 차이를 보이지 않았다. 이것은 저장 중 당분이 알콜과 탄산가스로 분해되었기 때문에 함량이 감소한 보여진다. 4℃에서 저장시, 일반적인 유통기간보다(10일) 긴 20일 동안 유리당의 변화를 보였으며 유리당은 12일 경에 sucrose, glucose와 mannose의 양은 1/2으로 감소하였다. 총산 및 pH 분석결과 각 저장온도에서 저장기간에 따른 pH의 변화는, 4℃에서 저장한 경우, 저장 4일경 pH 4.3에서 8일경 pH 3.8로 떨어지면서 저장기간 동안 서서히 감소되었다. 25℃에서 저장한 경우, pH 4.6~3.2 수준으로 4℃ 저장 온도보다 25℃ 온도에서 pH가 낮게 관찰 되었고 진세노사이드 분석결과 함량은 2.47 mg/g으로 측정되었다.
        109.
        2014.07 서비스 종료(열람 제한)
        Mungbean (Vigna radiata) is a fast-growing, warm-season legume crop that is primarily cultivated in developing countries of Asia. We constructed a draft genome sequence of mungbean to facilitate genome research into the subgenus Ceratotropis and to enable a better understanding of the evolution of leguminous species. The draft genome sequence covers 80% of the estimated genome, of which 50.1% consists of repetitive sequences. In total, 22,427 high confidence protein-coding genes were predicted. Based on the de novo assembly of additional wild mungbean species, the divergence of what was eventually domesticated and the sampled wild mungbean species appears to have predated domestication. Moreover, the de novo assembly of a tetraploid Vigna species (Vigna reflexo-pilosa var. glabra) provided genomic evidence of a recent allopolyploid event. To further study speciation, we compared de novo RNA-seq assemblies of 22 accessions of 18 Vigna species and protein sets of Glycine max and Cajanus cajan. The species tree was constructed by a Bayesian Markov chain Monte Carlo method using highly confident orthologs shared by all 24 accessions. The present assembly of V. radiata var. radiata will facilitate genome research and accelerate molecular breeding of the subgenus Ceratotropis.
        111.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        포름알데히드의 고농도와 저농도에 따른 식물의 생리적 반응을 보기 위하여 실험을 실시하였다. 실내식물은 관음죽, 팔손이나무, 스킨답서스를 이용하였으며, 포름알데히드는 0, 2(2.5), 10(12.3), 100(123) ppm(mg・m-3)농도로 처리하였다. 그 결과 포름알데히드 처리에 대한 잎 피해증상은 100 ppm의 고농도에서 5시간 처리 후 검은 반점으로 나타났다. 외관상 피해증상은 어린잎과 노화된 모두에서 나타났으며, 팔손이나무의 경우에는 줄기에서도 일부 나타났다. 피해 잎의 책상조직과 해면조직이 파괴되거나 변형되었다. 전체적으로 Peroxidase와 Catalase 함량은 관음죽>팔손이나무>스킨답서스 순서였으며, 처리농도가 높아질수록 함량도 대체로 증가하였다. 피해가 심한 스킨답서스의 경우 고농도 처리시에 기공이 닫히는 비율이 약 80% 가장 높았으며, Catalase 증가량도 가장 컸다. 결과적으로 100 ppm의 고농도에서 포름알데히드 흡수를 저해하기 위해 기공이 닫히거나 효소 함량의 변화가 일부 나타났으나, 저농도에서 적극적 흡수를 위한 반응은 보이지 않았다.
        112.
        2013.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        This study was performed to investigate the four-week repeated-dose toxicity of the crude antifungal compounds produced by Lactobacillus plantarum AF1 (Lb. plantarum AF1), a lactic acid bacterium isolated from kimchi, in male and female rats. Sprague-Dawley male and female rats were divided into four groups, with 10 animals in each group. The test article was administered once daily by gavage to rats at dosage levels of 0, 500, 1,000, and 2,000 mg/kg/day for four weeks. There were no test-article-related deaths or abnormal clinical signs in both the male and female rats during the observation period. Furthermore, no differences in the body weight changes, food intake and water consumption levels of the control and treatment groups were found. The hematological parameters, serum biochemical analysis results, histopathological examination results and all other findings also showed no significant or dose-dependent changes. There were also no changes in the organ weights upon the administration of the crude antifungal compounds produced by Lb. plantarum AF1. These results suggest that the oral administration of the crude antifungal compounds produced by Lb. plantarum AF1 had no adverse effects up to a dosage level of 2,000 mg/kg in both male and female rats.
        113.
        2013.02 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The present study was carried out to investigate the in vivo single-dose acute toxicity of Leuconostoc citreum GR1 (Leuc. citreum GR1), a lactic acid bacteria isolated from kimchi, in ICR male and female mice. The test article was orally administered once to both sexes of mice. The mortalities, clinical findings, autopsy findings, and body weight changes were monitored daily for two weeks. The male and female mice were gavaged with Leuc. kimchi GR1 of four doses (625, 1,250. 2,500 and 5,000 mg/kg). The oral LD50 of Leuc. citreum GR1 was considered higher than 5,000 mg/kg. No significant changes in the general conditions, body weights, clinical signs and presence of gross lesions were observed in both sexes of mice to whom Leuc. citreum GR1 was administered orally. The results indicated that the 5,000 mg/kg dose of Leuc. citreum GR1 showed no adverse effect.
        114.
        2012.04 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The in vivo single-dose acute toxicity of Lactobacillus plantarum AF1, a lactic acid bacterium isolated from kimchi, in ICR male and female mice was investigated. The test article was intraperitoneally or orally administered once to both sexes of mice. The motalites, clinical findings, autopsy findings, and body weight changes were monitored daily for 14 days. In the oral acute toxicity test, the male and female mice were gavaged with four doses (5.0, 2.5, 1.25 and 0.625 g/kg) of Lb. plantarum AF1. The oral LD50 of the Lb. plantarum AF1 was considered higher than 5.0 g/kg. In the intraperitoneal acute toxicity test, mice were injected intraperitoneally with dosages of 0.7, 0.9, 1.1, 1.3, 1.5, 1.7, 1.9, 2.1, 2.3 and 2.5 g/kg. The intraperitoneal 50% lethal dose (LD50) of the Lb. plantarum AF1 was >2.5 g/kg in the male and female mice. No significant changes in the general conditions, body weights, clinical signs, and gross lesions were observed in both sexes of mice to which Lb. plantarum AF1 was administered intraperitoneally or orally. The results suggest that the no-adverse-effect level of Lb. plantarum AF1 is estimated to be more than 5.0 g/kg in the oral route and 2.5 g/kg in the intraperitoneal route.
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